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US5012167A
Expired / Lapsed
US
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Sinusoidal signal decoder for 12-step motor commutation
Assignee: Ametek Pittman Inc
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Filing: 1990-03-30
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Granted: 1991-04-30
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Expires: 2010-03-30
Abstract
Abstract 12-step motor commutation is provided by a three-phase sinusoidal signal generator and related circuitry. Circuitry which compares the voltage outputs of two primary signals provides two additional switching points for every 360 electrical degrees. Three comparator circuits provide six additional switching points. Primary voltage outputs are weighted in the ratio of 2:1 prior to comparison.
Inventors
- 👤 Howard F. Hendricks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:37
CPC Classifications
H; H02; H02P; H02P6/00; H02P6/14
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
142 words
In an electric motor having a device for decoding sinusoidal signals from a motor shaft generator to derive a 12-step commutation, comprising: a. means for generating three sinusoidal output signals connected to the motor shaft, said signals being out of phase 120 electrical degrees and producing an output voltage proportional to the angle of said motor shaft; b. three voltage comparator circuits, each connected to receive a pair of said three sinusoidal output signals; c. means for combining the outputs of said three voltage comparator circuits with said three sinusoidal output signals to yield six equally spaced and non-overlapping voltage outputs; d. a PROM, detecting commutation switch points from said six voltage outputs, for producing twelve torque angles per rotor revolution for said 12-step commutation; e. a drive amp signaled by said PROM; and f. stator coils energized by said drive amp.
Claim 2
Dependent Claim
142 words
In an electric motor having a device for decoding sinusoidal signals from a motor shaft generator to derive a 12-step commutation, comprising: a. means for generating three sinusoidal output signals connected to the motor shaft, said signals being out of phase 120 electrical degrees and producing an output voltage proportional to the angle of said motor shaft; b. three voltage comparator circuits, each connected to receive a pair of said three sinusoidal output signals; c. means for combining the outputs of said three voltage comparator circuits with said three sinusoidal output signals to yield six equally spaced and non-overlapping voltage outputs; d. a PROM, detecting commutation switch points from said six voltage outputs, for producing twelve torque angles per rotor revolution for said 12-step commutation; e. a drive amp signaled by said PROM; and f. stator coils energized by said drive amp.
Claim 3
Dependent Claim
23 words
The motor of claim 1, wherein said means for generating three sinusoidal output signals comprises a permanent magnet rotor and three-phase field windings.
Claim 4
Dependent Claim
22 words
The motor of claim 2 further including a 2:1 input weighing resistor network connected to each of said three voltage comparator circuits.
Claim 5
Dependent Claim
28 words
The motor of claim 3 wherein said means for combining the outputs of said three voltage comparator circuits with said three sinusoidal outputs signals comprises EXCLUSIVE-OR decoding circuitry.
Claim 6
Dependent Claim
13 words
The motor of claim 4 wherein said motor is a brushless DC motor.
Claim 7
Independent Claim
100 words
A method of producing a 12-step commutation switching signal in an electric motor, comprising the steps of: a. generating three sinusoidal output signals with a shaft-mounted generator; b. combining said three output signals into three pairs; c. comparing the value of each pair of the output signals using a 2:1 weighing resistor network to achieve three signals from the comparison of each of the three pairs; and d. combining the three sinusoidal output signals with the three signals resulting from said comparison step by the process of EXCLUSIVE-ORing to yield a total of six output signals for said 12-step commutation.
Claim 8
Independent Claim
100 words
A method of producing a 12-step commutation switching signal in an electric motor, comprising the steps of: a. generating three sinusoidal output signals with a shaft-mounted generator; b. combining said three output signals into three pairs; c. comparing the value of each pair of the output signals using a 2:1 weighing resistor network to achieve three signals from the comparison of each of the three pairs; and d. combining the three sinusoidal output signals with the three signals resulting from said comparison step by the process of EXCLUSIVE-ORing to yield a total of six output signals for said 12-step commutation.
References Cited (Backward Citations)
US3264539A
Cited
US3466519A
Cited
US3662238A
Cited
US3621358A
Cited
JPS525417A
Cited
US4208621A
Cited
US4292575A
Cited
US4356437A
Cited
JPS5740392A
Cited
US4442386A
Cited
US4525657A
Cited
US4631458A
Cited
US4631459A
Cited
JPS6218989A
Cited
US4758768A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1994-04-29 | 1994-10-29 | 1995-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-04-29 | 1998-10-29 | 1999-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-04-29 | 2002-10-29 | 2003-04-30 | $7700.00 | Window Closed / Lapsed |